3,183 research outputs found
The 10th Biennial Hatter Cardiovascular Institute workshop: cellular protectionâevaluating new directions in the setting of myocardial infarction, ischaemic stroke, and cardio-oncology
Due to its poor capacity for regeneration, the heart is particularly sensitive to the loss of contractile cardiomyocytes. The onslaught of damage caused by ischaemia and reperfusion, occurring during an acute myocardial infarction and the subsequent reperfusion therapy, can wipe out upwards of a billion cardiomyocytes. A similar program of cell death can cause the irreversible loss of neurons in ischaemic stroke. Similar pathways of lethal cell injury can contribute to other pathologies such as left ventricular dysfunction and heart failure caused by cancer therapy. Consequently, strategies designed to protect the heart from lethal cell injury have the potential to be applicable across all three pathologies. The investigators meeting at the 10th Hatter Cardiovascular Institute workshop examined the parallels between ST-segment elevation myocardial infarction (STEMI), ischaemic stroke, and other pathologies that cause the loss of cardiomyocytes including cancer therapeutic cardiotoxicity. They examined the prospects for protection by remote ischaemic conditioning (RIC) in each scenario, and evaluated impasses and novel opportunities for cellular protection, with the future landscape for RIC in the clinical setting to be determined by the outcome of the large ERIC-PPCI/CONDI2 study. It was agreed that the way forward must include measures to improve experimental methodologies, such that they better reflect the clinical scenario and to judiciously select combinations of therapies targeting specific pathways of cellular death and injury
Search for New Physics in e-e- Scattering
Considering the physics potential of an e-e- collider in the TeV energy
range, we indicate a few interesting examples for exotic processes and discuss
the standard model backgrounds. Focussing on pair production of weak gauge
bosons, we report some illustrative predictions.Comment: 11 LaTeX pages; axodraw.sty and 6 figures included as an uuencoded
file; MPI-PhT/94-33 and LMU-09/9
Lepton-flavor violating decays as probes of quantum gravity?
Lepton flavor violating decays and are considered. It is shown that these decays can reach sizeable
magnitudes if some specific lepton-flavor violating 4-fermion operators are
generated by low scale quantum gravity effects, or by some other new physics at
a TeV scale.Comment: 18 pages, 1 figures, LaTeX, uses FEYNMAN package. New references
adde
Vector boson pair production in e-e- collisions with polarized beams
The -boson pair production in collisions with polarized beams is
investigated. The helicity amplitudes are derived for general couplings and the
conditions for a good high-energy behaviour of the cross-section are given. The
results are applied to the heavy vector boson production in the context of the
left-right symmetric model. The Ward identities and the equivalence theorem are
also discussed.Comment: 17 pages+ 8 figures(uuencoded compressed ps-file appended), HU-SEFT R
1994-09 (the original version of the file was unreproducable in some
computers
Inhibition of permeability transition pore opening by mitochondrial STAT3 and its role in myocardial ischemia/reperfusion
The signal transducer and activator of transcription 3 (STAT3) contributes to cardioprotection by ischemic pre- and postconditioning. Mitochondria are central elements of cardioprotective signaling, most likely by delaying mitochondrial permeability transition pore (MPTP) opening, and STAT3 has recently been identified in mitochondria. We now characterized the mitochondrial localization of STAT3 and its impact on respiration and MPTP opening. STAT3 was mainly present in the matrix of subsarcolemmal and interfibrillar cardiomyocyte mitochondria. STAT1, but not STAT5 was also detected in mitochondria under physiological conditions. ADP-stimulated respiration was reduced in mitochondria from mice with a cardiomyocyte-specific deletion of STAT3 (STAT3-KO) versus wildtypes and in rat mitochondria treated with the STAT3 inhibitor Stattic (STAT3 inhibitory compound, 6-Nitrobenzo[b]thiophene 1,1-dioxide). Mitochondria from STAT3-KO mice and Stattic-treated rat mitochondria tolerated less calcium until MPTP opening occurred. STAT3 co-immunoprecipitated with cyclophilin D, the target of the cardioprotective agent and MPTP inhibitor cyclosporine A (CsA). However, CsA reduced infarct size to a similar extent in wildtype and STAT3-KO mice in vivo. Thus, STAT3 possibly contributes to cardioprotection by stimulation of respiration and inhibition of MPTP opening
One-loop chiral amplitudes of Moller scattering process
The high energy amplitudes of the large angles Moller scattering are
calculated in frame of chiral basis in Born and 1-loop QED level. Taking into
account as well the contribution from emission of soft real photons the compact
relations free from infrared divergences are obtained. The expressions for
separate chiral amplitudes contribution to the cross section are in agreement
with renormalization group predictions.Comment: 15 pages, 3 figure
Supersymmetric Left-Right Model and its Tests in Linear Colliders
We investigate phenomenological implications of a supersymmetric left-right
model based on gauge symmetry
testable in the next generation linear colliders. We concentrate in particular
on the doubly charged triplet higgsino , which we find
very suitable for experimental search. We estimate its production rate in
, , and collisions and consider its
subsequent decays. These processes have a clear discovery signature with a very
low background from other processes.Comment: 23 pages + 11 pages of figures (available on request), HU-SEFT R
1993-1
Selectron production at an e-e- linear collider with transversely polarized beams
We study selectron production at an e-e- linear collider. With the help of
transverse beam polarizations, we define CP sensitive observables in the
production process e- e- --> selectron_L selectron_R. This process proceeds via
t-channel and u-channel exchange of neutralinos, and is sensitive to CP
violation in the neutralino sector. We present numerical results and estimate
the significances to which the CP sensitive observables can be measured.Comment: 14 page
The Noncommutative Standard Model and Forbidden Decays
In this contribution we discuss the Noncommutative Standard Model and the
associated Standard Model-forbidden decays that can possibly serve as an
experimental signature of space-time noncommutativity.Comment: 15 pages, 1 figure, Invited talk at 9th Adriatic Meeting and Central
European Symposia on Particle Physics and The Universe, Dubrovnik, Croatia,
4-14 Sep 200
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